Improved oscillating steam-valve



Nr PETERS. PHOTO-L ITNOGRAPHER, WASH yllbticd gitane aient dtllilitt.

ISAAO W. FORBES, O F LA PORTE, INDIANA.

Letters Patent No. 98,753, datedaanuary 11, 1870; arttclatefl December 14, 1869,.

IMPROVED OSCILLATING- 'STEAM-VALV.

The Schedule referred to -n these Letters Patent and making part of the same.

To altwhom it may concern.-

Be it known that I, IsAAc W. FORBES, of La Porte, in the county of' La Porte, and Stateoi Indiana, have invented new and useful Improvements in Oscillating Valves; and I dohereby declare the followingr to Abe a clear and exact description thereof, sufticient to enable others skilled in the art to which my invention appel'- tains,\to fully understand and use the same, reference l being had to the accompanying drawings, making apart of this speciticatiomin which- Figure 1 is au elevation of the ,device illustrating my invention.

Figure 2 is a central vertical section thereof. Figure 3 is atop o'r plan view. thereof. Figm'e 4 is a plan view of the valve-seat. Figure 5 is a bottom view 'of the valve.

Figure 6 is a top View of the balance-head of valveA 'parts in the several figures.

My invention consists in the construction, as hereinafter made known, of oscillating valves, whereby they are nearly balanced, and thus require but little power to move them, as will be hereinafter more fully described.

In t-he drawings- Afrepresents t-he spindle or axis of the valve, which may he made of wrought-iron or steel, passing through the valve-case E, working in a centre or step on the valve-seat.

B is an arm, which is keyed to said axis, and properly held thereonvby a nut, 0,01 other fastening. Thisy arm may be connected tu the working parts of the engine, or to the power which produces valve-motion. Instead of this arm, gearing may be employed.

D represents the stntiingbox, the object of which is to assist as a` bearing for the valve-stem, and'to prevent the leakage of steam which might otherwise take place.

The valve-case E has a flange, G, at the lower end, by which it is bolted to the face of the cylinder, and a boss on one side to receive the steam-pipe F, by means of which steam is admitted into the case. p

H is the iiauge ofthe valve-seat or cylinder-face,

and I I are nuts 4and studs, for fastening the valve case to the cylinder'.

K represents the head of the valve. It may be a portion of the lower part ofthe valve, and shrunk solid thereon, or placed loosely thereon, in which case lits' nppervportion will rest against acollar, L, on the spindle. f

The periphery `of the head has a steam-packing ring, K', which tits the case, bored out and nished, for the purpose of preventing the steam'from passing -to the `upper surface, or a series of grooves may be employed in place of said ring, if the balance-head is small, in

which case the groove should be in the head, and corresponding ones arein the case, and might be used for any-size4 valve instead of said ring, which some might prefer. It'the head is solid, as in iig. 10, the ring will be necessary.

M represents the hull or shell forming wall of theexhaust-chamber I.

M1, the top or ccver of port. Mit-he rim, extending around the outer portion of the outer the recess Z, through which v the-steam passes, for equalizing downward pressure; but this rim may be dispensed with, if desired.

I is the exhaust-chamber, which corresponds'in area with the area of the exhaust-port O, in addition to the divisionsv'l, between the exhaust-port O and receiving-ports S.

Iiecesses Q Q are formed in the fianges of valve-fA case and'valve-seat, to prevent leakage.

-A series of grooves, a a, is formed in the spindle, balance-head, and the collar L, corresponding to each other, and intended to prevent the passage of steam to the upper port-ion of the balance-head, between the balance-head and spindle.

Should water accumulate above the balance-head,

it will be conveyed, through the openings vIt ItV in the valve-stern, to the exhaust-port P, when used as a main valve.

The operation is as follows:

rlhe upper head of the valve fits the inside of the case with steam-packing ring, or otherwise, for the purpose of preventing steam from passing. Steam is introduced into the case through pipe F, and between the head and lower part oft-he valve. By these means thcvalye is nearly balanced, the upper head bein r smaller `than the lowerl ,iortion and able thus to n :a n produce a downward pressure suiiicient to hold 1t ou the val ve-scat.

As the valve is oscillating, the ports are opened byA `means of a recess, Z, corresponding with the ports.

Steam is received in theeportv over which the recess Z happens to he. The recess should not be moved i'urt-hcr than to give a full port.l

moved more than two-thirds ct' a port. Thenthe valve is moved back, the port S is closed, and the exhaust-chamber P, passing over the division T between the exhaustfport O and receiver-port S, so as to allow In fact it need not be steam to exhaust at the proper time, then the recess -Z passes over the opposite receiver-port S, which in valve-case; or it may pass to the case above the head,

and exhaust through 'the valve-seat, as represented in modifications, when the channel R will not be required. But if the balance-head and lower port are made of one piece, then' it will be necessary to make the space between the head and the lower portion larger, in order to allow afree passage for steam-to the upper portion of the head, or, ifnecessary, the valvestem may be larger and the'head be loose, and the channel lt made large and used for that purpose. In this case, the balance-head will have to be made as great in area as will compensate for the lift produced by the exhaust'steam. I

The lapse of the valve and the size of ports may be of any dimensions consistent with the size of the same.

The above description relates to valves having seats with two induction-ports and one exhaust-port, but

there may' be four induction-ports and no exhaust-port through the valve-seat.

Fig. 17 represents valve-seat when this modification is applied, where valves are used upon locomotives, which are liable to have the exhaust-pressure varied to suit thedierent grades and blasts to prevent them from rising fronr their face when there is a heavy exhaust-pressure upward.

In place of the exhaust l extending through the valve to the upper surface of the balance-head, for the purpose of equalizing pressure, a cap or bail may extend from the case to the upper portion of the valvespindle, with a set-screw through the same to press upon the centre of the spindle and prevent the valve from rising.

Two opposite ports, b b, must lead to one end of the cylinder, whilst the other two, c o, lead to the opposite, and the valve will require but one-half the motion to produce the openings that were produced when only two induction-ports were used. In this case, the valve hastwo openings, (l d, one each side of the centre, corresponding to the ports in the valve-seat. Each receives steam, and eachpassage is of the same area as the port-s in the valve-seat, through which steam lpasses into the ports.

lhere are two openings, ec, through the valve, quartering with the steam-passages d ll, each having twice the area of one induction-port. (See iig. 15.) These openings pass entirely through the yvalve for exhausting steam, through the top of the valve-case, and through the exhausting-pipe U. In this case, steam is admitted in the valve-case to the valv through the induction-pipe U.

To illustrate this more fully, the valve-seat, at its circumference, is spaced off into twenty-four equal parts, with lines drawn from the centre to the points marked oil'. Two of the spaces between the lines, at opposite points fromA the centre, are taken out at each quarter, leaving sufficient area at the centre to support the valve, and a rim at the circumference. There will be left `in the valve-seat, between each port, ajsurface twice the area of the port. The bottom partof the valve is to be marked off in. the same manner as the valve-seat, i.. c., into twenty-four parts.

Two openingsl are made at opposite points Vto each other, each one comprising two of the spaces Ithrough which steam passes into the ports. 4

On each side of the openings are left surfaces, f j; comprising three spaces each, and the four remaining. Aspaces e e upon opposite points are cored out through the valve for the exhaust steam to pass when there are four induction-ports.- But half the motion ofthe valve is necessary to produce the same area in the opening that is required with but two inductionports.

The valve-seat, fitting inside the valve-case, is raised about one-eighth of an inch, orl the valve-seat may be conical, or steam may be received through the top of the valveand passed through the same, through the ports of the engine, and exhaust below the head through the valve-case, as seen iu figs. 16 and 18, in

which case the steam passes into the pipe V, through the top of the valve, and through the small recesses el into the engine-ports,l and exhausting through valve, through spaces el, and the exhaustpipe below the head.

Fig. 13 is a top view of the valve in figs. 12 and 15.

Fig. 14 is a top view ofthe valve in figs. 16 and 18.

The principle of my invention is applicable to throttle-valves, which, as is well known, require no exhaustport, as represented in g. 19, which is a' central vertical, section. elusive, may revolve, ifv required.

Steam is received in the steam-pipe, and passes through the lower 'portion ofthe valve through lthe openings e?, and through openings e3 in the valve-scat, the openings in the valve and inthe valve-seat being of the same area and shape, and corresponding to each other; f f', covering the steam-passage in the valve-seat, as the valve is closed, the lower portion bein g keyed, or may be shrunk upon the valve-spindle.

An opening, g, is formed in the valve-case, above the'balance-head, to allow the escape or exit of condensed steam.

Having thus described my invention,

What I claim as new, and 'desire to secure byLetters Patent, i's- 1. The oscillating valve, constructed substantially as herein described.

2. lThe balance-head K, applied and operating substantially. as described.

vTo the above l have signed my name,this 27th day of August, 1869,

I. W. FORBES.

' Witnesses: t

PHIL. F. Laarzen, ADOLPHE ROEB.

The modilications in figs. 12 to 21, in- 

